Robust Fabrication of Novel Silica Nanosheets on Titanium Fibers for the Selective and Sensitive Determination of Ultraviolet Filters in Environmental Waters by Solid-Phase Microextraction

Abstract

A novel silica nanosheet coating was fabricated on a titanium (Ti) fiber substrate by electrophoretic deposition followed by annealing. Prior to the electrophoretic deposition, titania nanowire arrays were grown in-situ on the titanium wires by a hydrothermal process in alkaline solution and used as the active support for the subsequent deposition of the silica coatings. After annealing at 550 °C, the homogeneous silica nanosheets were formed on the titania nanowires coated titanium fiber. The fabricated fiber has controllable preparation reproducibility and long recycling stability. The extraction performance of the resulting coating was investigated using typical aromatic compounds as model analytes coupled to high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection. Excellent extraction selectivity and capability were demonstrated for the ultraviolet filters. Under the optimized extraction conditions for the analytes, good linearity was achieved across the concentration range from 0.02 to 400 μg·L−1 with correlation coefficients above 0.999 and limits of detection from 0.004 to 0.059 μg·L−1. Relative standard deviations below 7.3% were obtained for the determination of ultraviolet filters with the single fiber. The developed method was applied to the selective enrichment and sensitive determination of the target ultraviolet filters in real water samples with relative recoveries from 83.6% to 104%.